The piezoelectric sensor outputs piezoelectric signals in the microvolt to millivolt range.During acoustic emission detection process

the piezoelectric signal output from sensor needs to be preprocessed due to the transmission distance.In order to solve the problem of long-distance transmission of weak signals in measurement process

an interface design scheme common to signal lines and power lines is proposed

and the specific design process of each part is analyzed in detail to realize the amplification and transmission of low-frequency acoustic emission signals.The test results show that the circuit can realize the distortion-free amplification and isolation of the low-frequency acoustic emission signals of 1 kHz～2 MHz

which satisfies the requirements of acoustic emission signal transmission.